If you consult a periodic table of the elements you will see that the atomic number of helium is2. Thus, every helium atom has2protons. How many protons are there in a collection of 1.862 x 107helium atoms? Express your answer in scientific notation.

3.

Dr. Smith has asked you to prepare a2% potassium sulfate solution. What mass of potassium sulfate (in grams) must be dissolved in60ml of water to obtain a solution that will meet his approval?

4.

Une classe a cultivé40carrottes de sable et40in clay. After6weeks of growth they compared the plants to see which soil condition allowed the most root growth. The40du sable avait une masse totale de22.7g and the 35 from the clay (5 died) had a mass of16g. What was the average root mass per plant from each of the experimental groups? Round your answer to the nearest thousandth of a gram.

5.

John and Kelly are counting bubbles during their yeast fermentation experiment. According to the method, the number of bubbles passing through the apparatus per second indicates the rate of sugar consumption by the yeast. During their calibration step they each counted bubbles. John counted60bubbles in one minute. Kelly counted95bubbles in96seconds. Compare their calculated bubble-rates (in bubbles/second) and report which one was greater, (Ryan's or Katherine's) and by how much.

6.

Newton's 2nd law states that force (in newtons-N) equals mass (in kg) times acceleration (in m/s2). What is the force on a wall resulting from a1.1-kg brick hitting the wall and decelerating at10.04m/s2?